CRC polynomial value. The GPCRC support either a fixed 32-bit polynomial or a user configurable 16 bit polynomial. The fixed 32-bit polynomial is the one used in IEEE 802.3, which has the value 0x04C11DB7. To use the 32-bit fixed polynomial just assign 0x04C11DB7 to the crcPoly field. To use a 16-bit polynomial assign a value to crcPoly where the upper 16 bit's are zero.

The polynomial should be written in normal bit order. So for instance if you want to use the CRC-16 polynomial X^16 + X^15 + X^2 + 1 then we can first convert it to hex representation and remove the highest order term of the polynomial. This would give us 0x8005 as the value to write into crcPoly.

Enable/disable byte mode. When byte mode is enabled then all input is treated as single byte input, even though the input is a 32-bit word or a 16-bit half word. Only the least significant byte of the data-word will be used for CRC calculation for all writes.

CRC initialization value. This value is assigned to the GPCRC_INIT register. The initValue is loaded into the data register when calling the GPCRC_Start function or when one of the data registers are read while autoInit is enabled.

Reverse bits within each input byte. This setting enables or disable byte level bit reversal. When byte-level bit reversal is enabled then each byte of input data will be reversed before entering the CRC calculation.

Reverse byte order. This has an effect when sending a 32-bit word or 16-bit half word input to the CRC calculation. When set to true the input bytes are reversed before entering the CRC calculation. When set to false the input bytes stay in the same order.